Antibiotic-producing Symbionts
in Temperate Formicidae
By Ryan Croft with Dr. Elise Kimble, Dr. Allen Childs,
Dr. Steve Harbron, and Eric C. Atkinson
Introduction
•
Attine Ants
•
Bacterial Symbiosis
–
These ants house and grow bacteria on their
exoskeleton.
–
The bacteria provide protection against unwanted
bacteria and fungus in the their fungal gardens.
The Idea
•
Two questions:
–
Could temperate ants be a promising source
for novel antibiotics?
–
Do temperate ants use antibiotic active
bacteria symbiotically like Attine ants?
Hypothesis
•
I am proposing that ants could be a promising
source for novel antibiotics and that non-fungal
farming ants use antibiotic active bacteria
Materials and Methods
•
Collect ant samples
•
Plate ant samples
•
Isolate bacterial colonies
•
Test bacterial colonies
for antibiotic production
•
Identification through pcr
–
DNA extraction
–
pcr of the 16S rRNA gene
–
BLAST search
Collected Ant Samples
• Six different species
– Two known
Plated Ant Samples
•
Plated samples on seven different agar
media.
Isolated Bacterial Colonies
• Isolations based on morphology
• Huge bacterial variety
Tested for Antibiotic Activity
• Activity against three common pathogens
– Staphylococcus aureus
– Escherichia coli
Identification Through pcr
• DNA extraction
• pcr 16S rRNA gene
• BLAST search
Zone of inhibition
Results
Species Isolates Antibiotic Active Isolates % S. aureu s E. coli P. aeruginosa Western Harvester Ant 17 5 29% 5 0 0 Very Small Brown Ant 22 4 18% 4 0 0 Medium Black Ant 14 3 21% 2 2 0 Western Thatch Ant 23 7 30% 7 2 0 Small Black Ant 28 10 28% 10 4 1 Small Brown Ant 39 8 21% 8 1 0 TOTAL: 143 37 26% 36 9 1
Discussion
•
Hypothesis is supported
•
It is not only Attine ants that harbor
antibiotic active bacteria but also these
species that I tested.
•
We don’t know if these ants benefit from
these bacteria YET!
Fungicidal bacteria
Fungal contaminate
Zone of clearing
Acknowledgments
•
I want to thank all of you and especially…
Literature
• Currie, Cameron R., James A. Scott, Richard C. Summerbell, and David Malloch.“Fungus-Growing Ants Use Antibiotic-Producing Bacteria to Control Garden Parasites.” Nature 398, (1999). doi:10.1038/19519. • Currie, Cameron R., Michael Poulsen, John Mendenhall, Jacobus J.
Boomsma, and Johan Billen. “Coevolved Crypts and Exocrine Glands Support Mutualistic Bacteria in Fungus-Growing Ants.” Science 311, 28 (2006). doi:10.1126/science.1119744. 81-83.
• Hughes, W.O.H, A.N.M Bot, and J.J. Boomsma. “Caste-specific Expression of genetic Variation in the Size of Antibiotic-Producing Glands of Leaf-Cutting Ants” The Royal Society 277, (2009).
doi:10.1098/rspb.2009.1415. 609-615.
• Ramadhar, Timothy R., Christine Beemelmanns, Cameron R. Currie, and Jon Clardy. “Bacterial Symbionts in Agricultural Systems Provide a Strategic Source for Antibiotic Discovery.”Journal of Antibiotics 67, (2013). doi:10.1038/ja.2013.77. 53-58.
• Schuultz, Ted R. “Ants, Plants, and Antibiotics” Nature 398, (1999). http://www.nature.com/ nature/journal/v398/n6730/full/ 398747a0.html.747-748.
